Cross drive for lift jack apparatus

Claim 2

The combination with a generally rectangular load to be lifted of a lift jack apparatus comprising: a lift jack unit secured to each vertical corner of the load, each of said lift jack units including a vertically displaceable lift mechanism and rotatable drive means extending transversely of said lift mechanism rotatable about a horizontal axis of rotation to vertically displace said lift mechanism, adjacent pairs of said lift jack units arranged with said drive means horizontally aligned in facing relation to one another, and a cross drive assembly adapted for extension between each adjacent pair of lift jack units, said corss drive assembly including an elongated coupling member having opposite pivotal end portions, each of said end portions releasably engageable with one of said rotatable drive means of an adjacent pair of lift jack units whereby to transmit rotation of one of said drive means through said cross drive assembly for synchronous rotation of the other of said drive means.

Claim 3

The combination according to claim 1, said cross drive assembly being further characterized by including biasing means normally urging said pivotal end portions in opposite directions to releasably but firmly engage each of said drive means.

Claim 4

The combination according to claim 1, said drive means including a drive shaft on each of said lift jack units with the drive shafts of adjacent pairs horizontally aligned with one another, and said pivotaL end portions being defined by socket end portions each dimensioned to receive an end of a drive shaft on one of said lift jack units for driving engagement therewith.

Claim 5

The combination according to claim 3, further including a universal joint pivotally interconnecting each of said socket end portions to an opposite end of said elongated coupling member.

Claim 6

The combination according to claim 1, said elongated coupling member being defined by telescoping inner and outer concentric spring-loaded sleeve members, said inner sleeve member being outwardly biased toward an extended position with respect to said outer sleeve member.

Claim 7

Lift jack apparatus for a camper body wherein lift jack units are secured in lift-engaging relation to each of the four vertical corners of said camper body on a transport vehicle, each of said lift jack units including a lift mechanism, and the lift mechanisms of adjacent pairs of said lift jack units including transverse drive shafts horizontally aligned in facing relation to one another, the improvement comprising: a cross drive assembly drivingly interconnecting each of said adjacent pairs of lift jack units, said cross drive assembly including a coupling member defined by telescoping sleeves and means biasing said sleeves to a total effective length greater than the distance between said adjacent pairs of lift jack units, and socket end portions pivotally connected to opposite ends of said sleeves, each dimensioned for insertion of the inner facing end of a drive shaft therein and keyed for rotation with the drive shaft whereby rotation of one of said drive shafts is imparted through said cross drive assembly to the other of said drive shafts for synchronous displacement of said lift mechanisms on adjacent pairs of said lift jack units.

Claim 8

Lift jack apparatus for a camper body wherein lift jack units are secured in lift-engaging relation to each of the four vertical corners of said camper body on a transport vehicle, each of said lift jack units including a lift mechanism, and the lift mechanisms of adjacent pairs of said lift jack units including transverse drive shafts horizontally aligned in facing relation to one another, the improvement comprising: a cross drive assembly drivingly interconnecting each of said adjacent pairs of lift jack units, said cross drive assembly including a coupling member defined by telescoping sleeves and means biasing said sleeves to a total effective length greater than the distance between said adjacent pairs of lift jack units, and socket end portions pivotally connected to opposite ends of said sleeves, each dimensioned for insertion of the inner facing end of a drive shaft therein and keyed for rotation with the drive shaft whereby rotation of one of said drive shafts is imparted through said cross drive assembly to the other of said drive shafts for synchronous displacement of said lift mechanisms on adjacent pairs of said lift jack units.

Claim 9

Lift jack apparatus according to claim 6, further including corner brackets rigidly interconnecting each of said lift jack units to a vertical corner of said camper body, each corner bracket having a bottom horizontal flange abutting the underside of the camper at the lower edge of each vertical corner, each lift jack unit including an outer tubular member fastened in stationary relation to said bracket and an inner concentric tubular member slidable in telescoping relation through said outer tubular member, said lift mechanism for each unit further including a drivescrew displaceable by rotation of a drive shaft to vertically displace said inner tube with respect to the outer tube in lifting and lowering said camper body.

Claim 10

Lift jack apparatus according to claim 7, the lift mechanism of each lift jack unit further including a generally U-shaped, upstanding support for said drive shaft, said support being affixed to the upper end of said outer tube, bevel gear members arranged on said support and keyed to said drive shaft and drivescrew, respectively, to transmit rotation of said drive shaft to said drive screw, and a drive sleeve affixed to said inner tube and threadedly engageable with said drive screw to impart linear movement to said inner tube in response to rotation of said drivescrew.

Claim 11

Lift jack apparatus according to claim 6, one end of each drive shaft being generally rectangular in cross section, and the other end of each drive shaft being generally circular in cross section and having a transverse drive pin thereon, and the socket end portions on the cross drive assembly each having a generally rectangular cavity sized for close-fitting insertion of the rectangular end of the drive shaft, and one of said socket end portions having drive pin-receiving slots communicating with the cavity for driving connection with the other end of the drive shaft.

Claim 12

Lift jack apparatus for a generally rectangular camper body comprising a plurality of lift jack units, each lift jack unit including inner and outer telescoping tube members, said outer tube member rigidly secured to each of the four vertical corners of said camper body, a lift mechanism mounted on said outer tube member includiNg a drive shaft and a drivescrew drivingly engaging said inner tube vertically through the lower open end of said outer tube, the lift mechanisms of adjacent pairs of said lift jack units having said drive shafts horizontally aligned in facing relation to one another, drive means for rotating one of said drive shafts on each pair of lift jack units whereby to adjustably raise and lower said inner tube member, and a cross drive assembly drivingly interconnecting each of said pairs of adjacent lift jack units, said cross drive assembly including a coupling member defined by telescoping sleeves, means biasing said sleeves to a total effective length greater than the distance between said adjacent pairs of lift jack units, and socket end portions pivotally connected to opposite ends of said sleeves, each dimensioned for insertion of the end of a drive shaft therein and keyed for rotation with the drive shaft whereby rotation of one of said drive shafts is imparted through said cross drive assembly to the other of said drive shafts for synchronous displacement of said lift mechanisms on adjacent pairs of said lift jack units.

Claim 13

Lift jack apparatus for a generally rectangular camper body comprising a plurality of lift jack units, each lift jack unit including inner and outer telescoping tube members, said outer tube member rigidly secured to each of the four vertical corners of said camper body, a lift mechanism mounted on said outer tube member includiNg a drive shaft and a drivescrew drivingly engaging said inner tube vertically through the lower open end of said outer tube, the lift mechanisms of adjacent pairs of said lift jack units having said drive shafts horizontally aligned in facing relation to one another, drive means for rotating one of said drive shafts on each pair of lift jack units whereby to adjustably raise and lower said inner tube member, and a cross drive assembly drivingly interconnecting each of said pairs of adjacent lift jack units, said cross drive assembly including a coupling member defined by telescoping sleeves, means biasing said sleeves to a total effective length greater than the distance between said adjacent pairs of lift jack units, and socket end portions pivotally connected to opposite ends of said sleeves, each dimensioned for insertion of the end of a drive shaft therein and keyed for rotation with the drive shaft whereby rotation of one of said drive shafts is imparted through said cross drive assembly to the other of said drive shafts for synchronous displacement of said lift mechanisms on adjacent pairs of said lift jack units.

Claim 14

Lift jack apparatus according to claim 10, said inner tube member including a ground-engaging base plate thereon and a drive nut interposed between said drive screw and said inner tube to vertically displace said inner tube in response to rotation of said drivescrew.

Claim 15

Lift jack apparatus according to claim 11, said drivescrew arranged for axial extension in inner spaced concentric relation to said inner tube member.

Claim 16

Lift jack apparatus according to claim 10, further including a bracket fastened to each vertical corner of said camper body, each bracket including spaced upper and lower bands releasably clamping said outer tube member to each bracket.

Claim 17

Lift jack apparatus according to claim 13, each band defined by a generally C-shaped clamp having a pair of spaced connecting end portions at its terminal ends, and spacer means for mounting each clamp on said bracket whereby to clamp said outer tube member in spaced relation to said bracket.

Claim 18

Lift jack apparatus according to claim 14, said spacer means defined by a generally U-shaped mounting plate having opposite sides converging in a lateral direction away from connection to said bracket and terminating in a closed end portion having a concave surface conforming to the curvature of said clamp, and the connecting end portions of said clamp diverging rearwardly for connection to the convergent sides of the mounting plate with the closed end of the mounting plate aligned with the inner surface of said clamp, and adjustable means on said clamp engageable with said outer tube to urge it against the closed end of said mounting plate.

Claim 19

Lift jack apparatus for a camper body wherein lift jack units are secured in lift-engaging relation to each of the four vertical corners of said camper body on a transport vehicle, each of said lift jack units including a lift mechanism, and the lift mechanism of each lift jack unit including a transverse drive shaft rotatable to activate said lift mechanism in lifting and lowering the camper body, the improvement comprising, a rotary drive member including an elongated drive rod, drive means engageable with one end of the drive rod, and a universal joint having a drive socket releasably but drivingly connecting the opposite end of the drive rod and one end of a drive shaft, the drive rod being of sufficient length to permit lifting and lowering of the camper body between the ground and the elevated height necessary for placement on a truck bed.

Claim 20

Lift jack apparatus for a camper body wherein lift jack units are secured in lift-engaging relation to each of the four vertical corners of said camper body on a transport vehicle, each of said lift jack units including a lift mechanism, and the lift mechanism of each lift jack unit including a transverse drive shaft rotatable to activate said lift mechanism in lifting and lowering the camper body, the improvement comprising, a rotary drive member including an elongated drive rod, drive means engageable with one end of the drive rod, and a universal joint having a drive socket releasably but drivingly connecting the opposite end of the drive rod and one end of a drive shaft, the drive rod being of sufficient length to permit lifting and lowering of the camper body between the ground and the elevated height necessary for placement on a truck bed.

Claim 21

Lift jack apparatus according to claim 16, one end of each drive shaft being generally rectangular in cross section, and the other end of each drive shaft being generally circular in cross section and having a transverse drive pin thereon, said drive socket having a generally rectangular cavity sized for close-fitting insertion of the rectangular end of the drive shaft and having drive pin-receiving slots communicating with the cavity for driving connection with the other end of the drive shaft.